Typically, ducting is fabricated and assembled in a workshop. It is then shipped to site, where it is combined with fittings such as reducers, T-pieces, bends, elbows, etc., to form air and gas distribution systems.
The disadvantages of the existing products are:                In the workshop fabrication process, a number of machines such as guillotines, press brakes and seamers are used, together with processes such as cutting and welding, making handling and forming expensive.        Once made, storage, handling, road haulage and shipping costs can be high, because of the significant volumes taken up by large duct cross sections.        Offloading, storage and on-site handling to the point of installation is also costly.        